I want to share a strange issue I had - and the explanation I found.
Every time I powered on my MEGA65 I got a different start-up screen (Open ROMS) than after a reset (C65).
After spending some time thinking about this I remembered that the Open ROMS start-up was also shown when I had not inserted an SD card at all.
Removing my SD-card and re-inserting it fixed the issue - now power-on also starts up as C65 (using the ROM's on the SD-card).
Maybe a slightly loose SD-card can cause some timing issues that result in the MEGA65 booting as if there is no SD-card present on power-on - and on reset the timing works out better?
This was the start-up screen on power-on:
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And this was the start-up screen after reset:
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